close focus lens for 4x5 ?

[Neal Chaves]

In the 1980s, I had some nice work making 1:1 photos of rare postage stamps and coins. I used a monorail view camera with a roll back and 120 Kodachrome and a 65mm F8 Super Angulon at small stops with electronic flash. This lens is not known as being specially corrected for close-ups, but the results were excellent. The transparencies may still be in my "archives". If I come across them I will post hi-res scans.

[Dan Fromm]

If all lenses "have the rear node very close to the diaphragm" there would be no reason to publish a Flange Focal Length
spec on the datasheet, now would there???

Leigh, please don't misquote me. And there is indeed good reason to publish flange-focal distances. They help us know how much extension a lens needs to focus to infinity. Note, for lenses in shutter they're usually shorter than focal length because the diaphragm is in front of the flange.

My statement that the film-to-lensboard distance at 1:1 = FFL + OFL is absolutely correct for photographic lenses
of all types. No need to conjure up special cases where your generalities work.

Leigh, the law is the law. We stated it in different ways.

The flange focal length can differ substantially from the optical focal length, particularly for lenses shorter or longer than "normal"

This doesn't generally hold. What is true is that a barrel lens' flange can be anywhere between the barrel's front and rear and doesn't have to be near the diaphragm. It holds in two special cases, telephoto lenses and inverted telephoto lenses. By the way, your "optical focal length" isn't standard usage. FL and EFL are much more common.

[While the difference between FFL and OFL may be much larger numerically for longer lenses,
the difference at the short end can be substantial also.

If by "longer" you mean telephoto, we agree. If by "short end" you mean retrofocus, we agree. Otherwise you're mistaken.

For example, the FFL for the 65mm Fujinon SWD is 73.4mm, which is 18% longer than the optical focal length.

Then it is somewhat retrofocus. If you check the SA XL link I gave you, you'll see that the' lens internodal distance is substantial. Incidentally, I mistakenly stated that that lens' rear node is in front of the diaphragm. T'isn't, it is a moderate distance behind. I'm disappointed in you; I handed you a real error and you didn't bring it to my attention.

[Leigh]

Dan,

Drop the barrel lens nonsense. This is the 21st Century, not the 19th. You need to change your calendar.

I'm talking about modern lenses that real photographers might want to mount on real cameras to take real pictures.
I'm NOT talking about optical design, which is of little concern to a user.

The Flange Focal Length spec exists because it's a single number that shows whether or not a particular lens
will work properly on a particular camera with a particular bellows.

For any lens, the film to mounting plane distance when focused at infinity = FFL. That's the definition of FFL.
That parameter is valid for any photographic lens for any format, not just LF lenses.
It's true for Nikon, Canon, Hasselblad, or any other brand.

When the lens is focused for 1:1 reproduction, the distance from the film to the mounting plane = FFL + OFL.
That equation is valid by definition for any photographic lens for any format, not just LF lenses.

End of Optics 101. Perhaps you should take a refresher course.

Of course the rear nodal point can be used for determining the FFL, but that requires access to the lens design
documentation to get various dimensions, then making some calculations. The FFL does that for you.

- Leigh

[ic-racer]

How close? How much do you want to spend? Flat field or 3D?
If your range is one-half to 1:1 and you budget is limited and you are doing 3D work, then an inexpensive 105mm lens from a 6x9 would work well. It would require only about 210mm bellows draw at 1:1. The angle of view would be slightly 'long' for the format.

[Corran]

Come on, for this discussion it OBVIOUSLY doesn't matter about all the exact technical definitions Leigh! Unless he needs laboratory-precise 1:1 magnification, it isn't relevant.

[buggz]

Thanks to all for the valuable information.
I love this place.
I was able to get some play time in this weekend.
I found out that my existing setup will get me to within 10", if not closer.
This will be very sufficient for my purposes.
I was thinking, and trying different flower shots in the yard.
My immediate problem was, I had the wide angle bag type bellows on.
Not to mention the crazy 80degF+ temperature.
I see I wont be using my Sinar f2 much outside during the summer...
Anywho, Once I changed the bellows to the standard bellows, and added the 10" rail extension, I could "rack out" the standards of my Sinar f2 pretty far.
This seems to be great for my purposes.
For macros, I will still use my Canon 5DMkII, with cheap Chinese bellows.
Once again, thanks to everyone!

[rdenney]

Your F2 with standard bellows and 10" extension rail will provide about 20" of bellows draw. With the Sinar, you can add bellows and rail sections to your heart's content, using multipurpose standards to couple bellows sections together.

The standard WA Bellows (which is the Model 1) only provides about 10" of extension, or less. The WA Bellows 2 allows a bit more extension, as well as supporting ever shorter lenses.

It's possible to photograph some flowers at 1:1 using 4x5, but often the magnification is more like 1:2 or even 1:4. 20" of bellows draw will provide those magnifications for probably any lens in your kit.

For macro, it's usually more useful to think in terms of magnification ratio rather than distance to the subject. Subject distance (or working distance) is related to focal length, but magnification ratio can apply to any of your lenses. If you want 1:1, a 90mm lens needs about 180mm of extension (nominally), and a 250mm non-telephoto lens needs 500mm, or about 20". But at 1:1, the lens will be right in the middle (nominally) between the subject and the film, so a 90 will give you 180mm of working distance, and a 250mm lens at 1:1 will give you 20" of working distance, in both cases minus the length of the front cell. Macro photographers often want more working distance, favoring longer lenses.

Note that exposure changes by the square of the increase in extension (following the inverse square law). If you double the extension, you need four times the exposure (i.e., two stops). Since 1:1 requires doubling the extension, 1:1 therefore needs two stops of additional exposure. Exposures with large-format tend to be long. Look into something like the Wimberley Plamp to help keep your flower from waving in otherwise undetectable breezes.

I doubt that the optical qualities of any average large-format lenses are sufficiently suboptimal to make them an issue for flower photos in the wild. Other factors are far more likely to reduce sharpness to a greater extent.

If you want a lovely and inexpensive macro lens for your Canon, look into the old Tamron SP 90/2.5 Macro, in the Adaptall mount. Adaptall adapters for Canon EF are available. That will cost you about a third of Canon's cheaper 100mm macro lens, and it will be really excellent. (It's not as good for copy work--the field is not that flat.)

Rick "who has done a lot of large-format work in South Texas summers, and yes it can get hot under many types of focusing cloths" Denney

[Drew Bedo]

I came to LF on a very low budget, almost a DIY with wire and duct tape budget. I discovered "close-up accessory lenses" early on to use on my ruined and rebuilt no-name press camera with its shortened bellows.

While there are very good reasons for NOT useing these items, compositions and subjects that are centered in the field of view may work very well; insects, flowers and so on. Folks comment on the Bokke.

[Rich Long]

A top-hat lensboard can also be used to give a bit more reach beyond your bellows limit. (Apologies if that was already stated; my quick scan of the thread didn't see it.)

I have Nikkor 300M on a 30-mm tophat, making the lens more useful on my ShenHao 4x5. It would give a similar benefit to those wanting to shoot close-ups.

[Lynn Jones]

Due to the nature of the beast, all superwide lenses are optimized at or near 1:1 therefore you can used them for close focus. The formula is simple, Magnification plus 1 times focal length is the bellow draw for that focus, then focus by moving the camera in and out NOT BY LENS MOVEMENT!

Example: 2X with a 90mm wide angle: 2X+1=3, 3 times 90mm = 270mm (10.6 inches) bellows draw. Now slide the camera in and out to focus.

Lynn